SFL TeleKits and SFL Quantum finished TeleKits

for Short Focal Length Optics

28" f/3.6

14.5" f/3.7

20" f/3.95

20" f/3.95 Cage Interior

20" f/3.95 Cage Exterior

AstroSystems has
redesigned the TeleKit to meet the demanding requirements of the new short focal length mirrors now available. Optics of f/3.3-f/3.9 require a new approach to
telescope design. The larger, heavier secondary mirrors, stringent
collimation and focus tolerances are met by the new SFL TeleKit design. This new design has all the features of the standard
TeleKit plus:

Super Duty Secondary Holder - To properly support large, heavy secondary mirrors
several design changes have been incorporated. The larger holders have a proportionately thicker shell
and a 1/2"
mounting stud. The adjustment plate has been increased to 3/8" thick
and a rigid foam insert is used to position the mirror within the holder accurately
and maintain this position in any orientation. There are no tools needed to adjust holders
of 2.5" or larger in minor axis size; they come standard with thumbscrews.
All sizes feature our innovative four screw/two-axis
adjustment that greatly simplifies collimation. Two nuts with nylon washers position the holder laterally
and also allow easy adjustment of the rotation. The secondary mirror is
held securely yet safely against the front lip of the aluminum bezel with polyester
batting on sizes up to 4.0" and a rigid foam insert on sizes over 4.25".
Offset is included, necessary to evenly illuminate the field in short focal
length telescopes.

Super Duty Spider -
Our quality super duty spiders use the finest materials
and are built for optimum performance in f/3.3 - f/3.9 telescopes that require
extra support. Each vane has 2 fasteners for a total of eight.
They utilize 35% thicker high-tensile steel vanes, TIG welded
at the hub, giving extra tensile strength to hold critical collimation. The threaded stainless
steel vane tips (#10-32) are solidly TIG welded to the vanes, making this
the strongest spider on the market.

Focuser -
We offer the Moonlight CR-2 as standard on the short focal length TeleKits. The
fine 8:1 focus control is perfect for achieving critical focus. This is
one more of the demanding requirements of a short focal length telescope. The
Moonlight also handles weight well with the drawtube bearings being opposite the
drive axle. The extra weight of highly corrected eyepieces and a Coma
Corrector require a stable focuser with fine travel.

Cage Construction - The stiffness and rigidity of the upper cage
has been increased to match the demands of heavier secondary mirrors and
critical collimation needed with short focal length optics. Thicker spider
supports (100%), and a thicker light baffle (35%) plus keeping the cage height to
12" on all sizes achieve the necessary strength and stiffness. The filter
slide is a naturally stiff mount for the focuser and is enhanced by heavier
mount hardware. The supplied Moonlight CR-2 focuser has 1:1 coarse
focusing and 8:1 fine focusing. The optional
Feathertouch focuser has 1:1 coarse focusing and 10:1 fine focusing. Both
feature a compression ring drawtube and adapter,
necessary for the critical focus and collimation of short focal length optics.

Primary Mirror Cell - The needed critical collimation is achieved
by edge support that keeps the primary mirror centered and extra fine collimation movement. Our zero stretch stainless band sling keeps the
primary perfectly centered and achieves uniform optical support over a large
portion of the edge. The collimation bolts feature 50% finer movement to
easily achieve critical collimation. 16" to 22" cells feature 18
point flotation and the 24"-32" have 27 point flotation, combined with
the integrated cooling system give your short focal length optic the environment to perform at
its peak.

Truss Fasteners
- The short focal length TeleKits have indexed fasteners to precisely locate the
truss, holding critical collimation. The size and thickness of the fasteners has
been increased to further augment collimation.

Mirror Box / Rocker Box /
Groundboard-
The TeleKit is constructed of Baltic Birch plywood, offering strength,
stiffness and natural vibration damping. The altitude bearings and rocker
box sidewalls and bottom (24"+) are double thick, giving crisp, precise motion.
This is further enhanced by our hybrid bearing system of three sets of ball
bearings on the groundboard, with adjustable friction, and 2 bearing sets and 2
PTFE pads on the altitude movement.

You can also customize the design and
feel confident adding any options desired. A 30-50% savings will be
realized over purchasing a premium finished truss tube telescope. We
supply all the hard to find or fabricate components, including a light shroud
for the trusses and 10" transport wheels and handles. We also supply
all the precision cut wood components which are routed with CNC technology.
Only the highest quality stainless steel hardware is included. A complete list of supplied
components and materials is in the frequently
asked questions.click
here

These kits include everything but the
optics, AstroSystems can supply the optics or direct you to several
opticians to obtain your primary mirror.

SFL Quantum Finished TeleKit for
Short Focal Length Optics

Do you like all the outstanding features
of the AstroSystems SFL TeleKit but
don't have the time, space or inclination to build one? Not a
problem! We now offer the Quantum finished TeleKit for short focal
length optics in 16", 18" (17.5"), 20", 22", 24",
25", 28", 30" and 32" completely finished.
Ultra-smooth, four coat polyurethane finish offers unsurpassed protection.
We use our own specially formulated penetrant/water resistant primer and 3
topcoats of premium spar polyurethane for unsurpassed water resistance and
durability. Truss telescopes may look alike from a distance, but the
beautiful golden blonde Baltic Birch complimented by the
black accents always stands out among Truss Newtonians. The closer you
look, the more obvious the superior workmanship, finish and performance becomes.
Sky and Telescope magazine called the TeleKit a "heirloom Dobsonian"
in their June 1998 review. Ready to drop in your optics, or we can
supply optics from one of many recommended opticians. The finished
TeleKit features the same precise CNC routed parts as the TeleKit. A Lycra
light shroud and transport system are standard. Only the highest quality
stainless steel hardware is used.